Getting Serious About Transposable Elements

Post Provided by: Gabriel Rech and José Luis Villanueva-Cañas

So Simple yet so Complex

A long standing research topic in evolutionary biology is the genetic basis of adaptation. In other words, how does a novel trait appear (or spread) in response to an environmental change? Despite the rapid advances in sequencing over the last two decades, we have only been able to fully characterize a few adaptations.

As stated by Richard Dawkins in Climbing Mount Improbable, while natural selection is a very simple process, modeling natural selection and determining its causes, effects and consequences is an extremely difficult task. Also, most of our efforts so far have been focused on just one type of genetic variation: single nucleotide polymorphisms (SNPs). Other types of variations such as transposable element (TE) insertions have received much less attention. Paradoxically, some great examples of the role of TEs in adaptation have been right under our noses the whole time, in basic biology textbooks. Continue reading

Advertisements

Evolutionary Quantitative Genetics: Virtual Issue

Post provided by Michael Morrissey

©Dr. Jane Ogilvie, Rocky Mountain Biological Laboratory

Evolutionary quantitative genetics provides formal theoretical frameworks for quantitatively linking natural selection, genetic variation, and the rate and direction of adaptive evolution. This strong theoretical foundation has been key to guiding empirical work for a long time. For example, rather than generally understanding selection to be merely an association of traits and fitness in some general way, theory tells us that specific quantities, such as the change in mean phenotype within generations (the selection differential; Lush 1937), or the partial regressions of relative fitness on traits (direct selection gradients; Lande 1979, Lande and Arnold 1983) will relate to genetic variation and evolution in specific, informative ways.

These specific examples highlight the importance of the theoretical foundation of evolutionary quantitative genetics for informing the study of natural selection. However, this foundation also supports the study other critical (quantification of genetic variation and evolution) and complimentary (e.g., interpretation when environments, change, the role of plasticity and genetic variation in plasticity) aspects of understanding the nuts and bolts of evolutionary change. Continue reading

Conifers for Christmas: Evolution above the level of species

Post provided by  Aelys Humphreys

Conifers for Christmas

It’s somehow fitting that the centre piece of an ancient midwinter tradition in Europe – that of decorating and worshipping an evergreen tree – is an ancient seed plant, a conifer. In Europe, we tend to think of conifers as “Christmas trees” – evergreen trees with needles and dry cones, restricted to cold and dry environments – but conifers are much more diverse and widespread than that. There are broad-leaved, tropical conifers with fleshy cones and even a parasitic species that is thought to parasitise on members of its own family!

Conifer diversity. Classic Christmas tree style conifers in the snow; a broadleaved, tropical podocarp (© Ming-I Weng); the only parasitic gymnosperm, Parasitaxus usta (©W. Baker).

Conifer diversity. Classic Christmas tree style conifers in the snow; a broadleaved, tropical podocarp (© Ming-I Weng); the only parasitic gymnosperm, Parasitaxus usta (©W. Baker).

However, while today’s distribution of conifers is global – spanning tropical, temperate and boreal zones – it is fragmented. The conifer fossil record extends well into the Carboniferous and bears witness to a lineage that was once much more abundant, widespread and diverse. So we can tell that today’s diversity and distribution have been shaped by hundreds of millions of years of speciation, extinction and migration. Continue reading

Topography of Teeth: Tools to Track Animal and Ecosystem Responses to Environmental Changes

Below is a press release about the Methods paper ‘Inferring diet from dental morphology in terrestrial mammals‘ taken from the Smithsonian Institution.

By charting the slopes and crags on animals’ teeth as if they were mountain ranges, scientists at the Smithsonian’s National Museum of Natural History have created a powerful new way to learn about the diets of extinct animals from the fossil record.

Understanding the diets of animals that lived long ago can tell researchers about the environments they lived in and help them piece together a picture of how the planet has changed over deep time. The new quantitative approach to analysing dentition, reported on 21 November in the journal Methods in Ecology and Evolution, will also give researchers a clearer picture of how animals evolve in response to changes in their environment.

gorilla

A 3D reconstruction of the teeth of a western gorilla (Gorilla gorilla).

Continue reading

Flawed Analysis Casts Doubt on Years of Evolution Research

Below is a press release about the Methods in Ecology and Evolution paper ‘‘Residual diversity estimates’ do not correct for sampling bias in palaeodiversity data‘ taken from the University of Bristol.

Years of research on the evolution of ancient life, including the dinosaurs, have been questioned after a fatal flaw in the way fossil data are analysed was exposed by scientists from the universities of Reading and Bristol.

Studies based on the apparently flawed method have suggested Earth’s biodiversity remained relatively stable – close to maximum carrying capacity – and hinted many signs of species becoming rapidly extinct are merely reflections on the poor quality of the fossil record at that time.

However, new research by scientists at the University of Reading suggests the history of the planet’s biodiversity may have been more dynamic than recently suggested, with bursts of new species appearing, along with crashes and more stable periods.

Continue reading

RPANDA: A Time Machine for Evolutionary Biologists

Post provided by HÉLÈNE MORLON

Yesterday saw the start of this year’s annual Evolution meeting and to celebrate Hélène Morlon has written a blog post discussing the amazingly versatile RPANDA package that she is developing with her research group. A description of RPANDA was published in the journal earlier this year and, like all our Applications papers, is freely available to read in full.

If you are attending Evolution, as well as attending the fabulous talks mentioned by Hélène below, do stop by booth 125 to see our BES colleague Simon Hoggart. Simon is the Assistant Editor of Journal of Animal Ecology and would be happy to answer your questions about any of our journals or any of the other work we do here at the BES.

RPANDA: a time machine for evolutionary biologists

Imagine “Doc”, Marty’s friend in Back to the Future, trying to travel back millions of years in an attempt to understand the history of life. Instead of building a time machine from a DeLorean sports car powered by plutonium, he could dig fossils, or more likely, he would use molecular phylogenies.

Molecular phylogenies are family trees of species that can be built from data collected today: the genes (molecules) of present-day species (Fig 1). They are often thought of as trees, in reference to Darwin’s tree of life. The leaves represent the present: species that can be found on Earth today. The branches represent the past: ancestral species, which from time to time split, giving rise to two independent species. The structure of the tree tells us which species descend from which ancestors, and when their divergence happened.

birds_phylog

Fig 1: The phylogenetic tree of all birds (adapted from Jetz et al. 2012). Each bird order is represented by a single bird silloutter and a specific colour (the most abundant order of Passeriformes, for example is represented in dark orange). Each terminal leaf represents a present-day bird species, while internal branches represent the evolutionary relationships among these species.

Continue reading

Measuring Survival Selection in Natural Populations: How important is recapture probability?

Post Provided by John Waller

The “Lande-Arnold” Approach

Damselflies marked in the field, which will hopefully be recaptured later. This small insect at our field site had only about 10% recapture probability.

Damselflies marked in the field, which will hopefully be recaptured later. This small insect at our field site had only about 10% recapture probability.

The quantification of survival selection in the field has a long history in evolutionary biology. A considerable milestone in this field was the highly influential publication by Russel Lande and Steve Arnold in the early 1980s.

The practical implementation of Lande and Arnold’s method involved simply fitting a linear model with standardized response (survival) and explanatory (trait) variables values with quadratic terms (multiplied by two). This straightforward method allowed evolutionary biologists to measure selection coefficients using commonly available statistical software and these estimates could be used directly within a quantitative genetic framework.  Continue reading

Virtual Issue: Evolution 2013

Evolution 2013 coverTimed for Evolution 2013, we have just put up a Virtual Issue highlighting some of the papers with an evolutionary theme published in the last year.

The link between ecology and evolution is important to MEE: the research papers we have highlighted include excellent examples of these such as modelling dispersal and testing for niche conservatism. Barcoding methods are included, which increasingly are used in an ecological context; the Applications and research papers include a high proportion of papers that describe methods for comparative analyses, which underpin both ecological and evolutionary studies. This selection therefore showcases the excellent range of research that we have published spanning both ecology and evolution.

Enjoy & enjoy Snowbird!

Top 10 speciation and evolution papers

Methods will be attending the next ITN Speciation conference 2012 in Jyväskylä, Finland and to mark the occasion, the editorial team has put together a list of some our most relevant work in speciation and evolution.

Applications – concise papers describing new software, equipment, or other practical tools:

Molecular ecology, phylogeny and evolution

If you are going there, stop by to talk to me, Graziella Iossa, journal coordinator. See you on 26-28 February, 2012, at the University of Jyväskylä, Finland!

Volume 3 Issue 1: Now online

It seems that from the number of submissions we receive at the journal, Methods in Ecology and Evolution has filled an important niche. As our editor-in-chief, Rob Freckleton, wrote to introduce our second volume: “those doing science need to be kept up to date on new approaches, and those developing new methods need a place to publish, as well as be supported in getting their methods used”. The journal appears to have done just that: not only have we published some very popular articles (see our recent posts on 2011 top cited papers part 1, part 2 and part 3) but we have also seen a keen interest from our authors in utilising the online extras that we offer to disseminate their work.

As always, in issue 3.1 we cover a very broad range of articles – the scope includes everything from statistics, to ecophysiology and stable isotope methods. The applications of the methods are as varied as reconstructing snow depth surfaces, tracking migratory songbirds, estimating immigration in neutral communities and assessing the effects of watershed and reach characteristics on riverine assemblages. Being the first issue of the year all content is free to access.

One of our big aims is to promote the uptake of methods. On our video and podcast page, we have support for the papers in this issue, including:

Our first Open Access article by Erica Spotswood and colleagues, How safe is mist netting? Evaluating the risk of injury and mortality to birds, attracted a lot media attention. You can read the press coverage for this article on our News and Highlights page.

This issue also contains a free phylogenetic application: MOTMOT, a model of trait macroevolution on trees by Gavin Thomas and Rob Freckleton. Check out our Applications page describing the latest software tools. It’s worth remembering that all Applications are free.

Finally, Mitch Eaton and William Link provided the catchy photograph that make this issue’s front cover. You can read more about the cover on a separate post, available tomorrow!

We hope you enjoy reading this issue!